The process of changing the color of hair, can involve depositing an artificial color onto the hair which provides a different shade or color to the hair, and/or lifting the color of the hair, such as lightening the color of dark hair to lighter shades.
In general, hair lightening or color lifting compositions and hair dyeing compositions possess an alkalinity such that these compositions have a pH value of above 7, typically being at pH 9 and above, and may generally require the presence of an alkalizing agent such as ammonia or an ammonia gas-generating compound and/or an amine or ammonium-based compound in amounts sufficient to make such compositions alkaline. This alkalizing agent causes the hair shaft to swell, thus allowing active agents into the hair.
Imparting a color change or color effect on hair can be done using permanent and semi-permanent or temporary hair coloring products. Conventional permanent hair coloring products are dye compositions comprising oxidation dye precursors, which are also known as primary intermediates or couplers. These oxidation dye precursors are colorless or weakly colored compounds which, when combined with oxidizing products, give rise to colored complexes by a process of oxidative condensation. The oxidizing products conventionally use peroxides such as hydrogen peroxide as oxidizing agents. Such permanent hair color products also contain alkalizing agents which causes the hair shaft to swell, thus allowing the small oxidative dye molecules to penetrate the cuticle and cortex before the oxidation condensation process is completed. The resulting larger-sized colored complexes from the oxidative reaction are then trapped inside the hair fiber, thereby permanently altering the color of the hair. In contrast, semi-permanent dyeing uses direct dyes, which are nonionic or ionic dyes and colored compounds capable of producing a more or less pronounced change of the natural color of the hair, resistant to shampoo-washing several times. These dyes may or may not be used in the presence of an oxidizing agent. In contrast with oxidation dye precursors, a direct dye is a relatively voluminous molecule that does not penetrate easily into the core of the fiber.
Consumers are always looking for new shades of hair color, which can be obtained by known dye molecules. However, one issue that can occur with these relatively complex dye molecules is that they can be difficult to formulate into stable hair color base. Thus, it would therefore be desirable to provide the consumer with stable hair color-altering compositions that allow for shades not previously attainable.